DXC100: Why were the CO2 readings on my unit correct recently but now suddenly seem incorrect?

This unit has an automatic calibration process that sets the lowest value recorded in a week at 450 ppm, which is supposed to be achieved in the presence of fresh air. If, during a given week, the sensor has never been in contact with fresh air (including the absence of living creatures for 12 hours in a closed room), the calibration process cannot take place correctly. Also note that for this automatic calibration process to work properly, the sensor must be plugged in for 7 days straight.

To have your unit recalibrated correctly, please do the following

1. Use an extension cable instead of plugging the unit directly into your computer.

2. Plug your unit into a location where it will have power for a full week. The self-calibration process takes place every 7 days without interruption of power. When you shut down your laptop, the unit will stop receiving power and the recording and calibration process will start again each time.

3. During the 7 days of power, make sure your sensor has access to fresh air: this will be its baseline for calibration. Fresh air is outdoor air, or it can simply be placed in a room where no living beings are present for 12 hours. In other words, it should not be placed in a place where there are people 100% of the time.

REMARK: The DXC100 was designed for offices (which are usually empty on weekends) and homes (when, before the days of COVID, they were empty during the weekdays).